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unit has unloaders. noticed it was cycling on low psi
it has a checkvalve inline to cond.pump unit down front seated both service valves evacuated comp.have linetaps on psi switches to both sides of comp, put nitrogen in discharge side low side would equelize bad valves right?took center head off because that is where psi fiting goin to valves looked ok replaced intake and turned over discharge valves is it possible that all valves are bad on two outerheads or am i looking in the wrong area. operating psi 65 low 245high outside temp aprox.74(inside carshop railroad equip)thanks for the help and information i get from all you guys happy new year.

I think that you are going the wrong way on this one, just based on what you wrote. With unloaders, I don't see anyway out of hand way to condemn the valves on this compressor, just because of immediate equalization. Firt thing that I would suspect...you are cycling out on LP, are you short on gas? What are you running ,R22 AC? Lets get some more info on this one before we start changing compressors or valve plates. Good Luck.

pulled 27# 22 pretty much afull charge a/c.
i'm not sure of what kind of info you need,but i have the comp, isolated from the rest of the system, and although i only ran system for a short time with the above psi i only have till friday to troubleshoot this one and 9 more units so how should i qualify the valves, i am sure that if i front seat suction side it will pull down.could it be a conecting rod or piston? thanks for the reply.three o'clock comes early.

rail,
I am glad to see that you have checked this. Here is a question, is it possible you have a bad lp switch? Is it DEFINATELY going out on LP? Some of these set ups have safeties in series, is it a thermal overload taking it out? Do you have a low pressure situation? The reason I ask, is that I think in a true to form high to lowside leak (as in blown valves) you would NOT kick out on LP. Your backpressure would be HIGH if anything. Verify LP is working properly. I hope that this helps. good luck.

Operating at 65 psi??? What is the td over the coil?? what is superheat? what is subcooling? What is current draw compared to performance curves? What the the airflow over the evap? Is evap clean? Are filters clean? What is the setting of the LPCO? What pressure does it kick out at?? Really need some mor 411.

If you really know how it works, you have an execellent chance of fixin' er up!

i have comp, isolated from system i'am trying to qualify valves. when i charge from discharge port my psi rises on low side both service valves are front seated.coils are all clean lps is encapsulated ci 35-co 15

carlylle valve plates

A quick point-
apparently carlyle has relaxed approach to their valve plates-
new out of the box you will see daylight under the disch reeds on most new plates... they will state that once disch pressure is applied atop valve plate the diff will cause the reeds to seal. Hmmph. have coworker who burned thru near 2 doz on counter to find 3 that werent like this.
so it follows that if there is insufficient diff across plates/reeds there will be leakage.

I didnt say I condone it nor like it just the answer I have gotten from carlyle (except the last leakage part- when put to them like this the rep provided silence....).

so much for quick point. Havent looked at 06D in AC appl.
for long time, this is ref I speak to but can't be too diff.

If you can run it shoot the heads with infrared to find the abnormal head and pull it if you think thats the prob-hmmm
looks like I ramble for nothing.......*uh, never mind.....

Re: carlylle valve plates

Originally posted by thegoodhumorman A quick point-
apparently carlyle has relaxed approach to their valve plates-
new out of the box you will see daylight under the disch reeds on most new plates... they will state that once disch pressure is applied atop valve plate the diff will cause the reeds to seal. Hmmph. have coworker who burned thru near 2 doz on counter to find 3 that werent like this.
so it follows that if there is insufficient diff across plates/reeds there will be leakage.

I didnt say I condone it nor like it just the answer I have gotten from carlyle (except the last leakage part- when put to them like this the rep provided silence....).

so much for quick point. Havent looked at 06D in AC appl.
for long time, this is ref I speak to but can't be too diff.

If you can run it shoot the heads with infrared to find the abnormal head and pull it if you think thats the prob-hmmm
looks like I ramble for nothing.......*uh, never mind.....

great info turns out check valve failed and took out valves replaced checkvalve charged ran and frontseated intake no pumping 50 psi on back psi 150 discharge and stayed there would pump down. outside heads where running 157-173 center head 273. is it poss connecting rods or bad pistons.